Learning Processing: A Beginner's Guide to Programming Images ...

216 Learning Processing
Exercise 13-7: Use the sine function to create a “ breathing ” shape, that is, one whose size oscillates.
We can also produce some interesting results by drawing a sequence of shapes along the path of the sine
function. See Example 13–7 .
13.10
Example 13-7: Wave
// Starting angle
float theta = 0.0;
void setup() {
size(200,200);
smooth();
}
void draw() {
background(255);
// Increment theta (try different values for " angular velocity " here)
theta + = 0.02;
noStroke();
fill(0);
float x = theta;
// A simple way to draw the wave with an ellipse at each location
for (int i = 0; i < = 20; i + + ) {
// Calculate y value based off of sine function
float y = sin(x)*height/2;
// Draw an ellipse
ellipse(i*10,y + height/2,16,16);
// Move along x-axis
x + = 0.2;
}
}
Exercise 13-8: Rewrite the above example to use the noise( ) function instead of sin( ) .
Recursion
fi g. 13.14 The Mandelbrot set:
http://processing.org/learning/topics/mandelbrot.html
fi g. 13.13
A for loop is used to draw all the points along a sine
wave (scaled to the pixel dimension of the window).